The east and south of the country had the best of the bank holiday weekend sunshine yesterday but in other parts it was "disappointing and dull", according to Met Eireann.
There was a lot of cloud and drizzle in the north-west. However, temperatures were high everywhere, the highest being in Kilkenny, where it reached the "high teens".
After a dull start today, bright or sunny intervals will develop. Mist and drizzly rain will affect Atlantic coasts at times and a few showers could take place in the afternoon. It will be rather warm and humid again with top temperatures between 15 Celsius and 19 Celsius in a gentle south to south-east breeze.
More than 500,000 passengers were expected to travel by air, bus and rail routes over the weekend.
AA Roadwatch said traffic wasn't too heavy yesterday. "We thought it would have been heavier. The N11 - the Dublin to Wexford road - was the busiest, but this was mainly people out driving for the day."
The biggest congestion took place in Killarney, where the Rally of the Lakes was taking place, and the Killarney-Kenmare road was closed. Some motorists were delayed for two to three hours.
Friday evening and Saturday saw extremely heavy traffic and there were up to three- or four-mile tailbacks at Kinnegad, now recognised as the biggest bottleneck in the State.
AA Roadwatch says today will see the "real rush" from mid-afternoon to evening. It appealed to motorists to start out early and give themselves plenty of time to get back home.
"Safety is the main concern. They should not try to make up time lost in tail-backs."
Kildare has not been as bad as at the last bank holiday, when repair work was being carried out on Kyle Bridge. The repair work has been completed two weeks ahead of schedule.
The major retailers - Brown Thomas, Marks & Spencer, Dunnes Stores and Tesco - were open for business on the weekend.
May Day is the newest of our public holidays. It was introduced in 1994. In England it was brought in 1978.
The State is at the bottom of the European Union league of bank holidays, with only eight until May Day was granted. Belgium, France, Germany and Luxembourg have 10.
Britain basked in temperatures of 2021 Celsius and the mercury is expected to soar even higher today with the exception of east coast seaside resorts which are forecast to remain a cool 12 Celsius. It has been forecast that May Day Bank Holiday will be the third hottest since the holiday was created in 1978.